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The hull of the tank has 6 mm of armour added to the sides. The side armour is attached right to the hull and covers the space from the bogey mounts to the rivets on the edges of the hull. The front and rear of the hull has sloped armour installed. The armour plates are attached using bulletproof rivets and electric welding. The part of the hull that protrudes above the radiator is shielded from four sides with 6 mm armour. 3 armour plates are added to the front, 2 to the sides, and one on the ventilation cap. The left plate and cap plate are bent to follow the shape of the parts they are installed on. The upper horizontal parts of the hull and the floor also have applique armour. Additional 6 mm plates are welded onto the observation port cover and the left side of the hatch edge. Mudguards are installed along the length of the hull on the buoy carriers.

The turret has 6 mm of armour added to the sides. The front of the turret is converted similarly to the T-40 turret, and the DShK machinegun is installed, with no DT. The machinegun has no elevation mechanism, but has a shoulder stock. Aside from the existing travel locks, a stopper was added to the turret to fix it in place while shooting. A travel lock was added for the DShK machinegun. The DT machinegun opening is preserved, but closed with a plug. The DT remains in the tank, in case it needs to be removed and taken from the tank, or, in an emergency, installed in its old location. This kind of placement was caused by the fact that the old location made it difficult for the gunner to enter or exit the turret and made his station cramped. A special mount was added for the DShK ammunition box. A rack with 10 boxes was added instead of the second driver's seat.

In the event that the current armament and 15 DT magazines remain, the turret can receive applique armour without any design changes.

The mass of the T-37 tank increases by 350 kg after completing the work, stemming from these calculations:

Applique armour weight: up to 400 kg

Armament, ammunition, and mounts: up to 120 kg

Removed components and parts: 170 kg

Additional work to modernize the T-37 tank (with re-armament):

Cutting and mechanical: 252 hours

Smithing: 8

Lathing: 18

Milling: 4

Planing: 3

Welding: 42

Installation: 146

Total: 473 hoursNote: Major repairs of a T-37 tank take 573 hours. The modernization adds an extra 79% to the time it takes to repair the tank.

Additional work to modernize the T-37 tank (without re-armament);

Cutting and mechanical: 173 hours

Smithing: 4

Lathing: 12

Milling: 2

Planing: 1

Welding: 26

Installation: 96

Total: 316 hoursNote: Major repairs of a T-37 tank take 573 hours. The modernization adds an extra 55% to the time it takes to repair the tank.